JP4414610B2 - Forward / backward switching device for vibration compaction machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to forward / reverse switching in a vibration compacting machine that changes the phase of rotation of one eccentric pendulum with respect to the other eccentric pendulum of a pair of eccentric pendulums in a vibration generator and moves the body forward and backward by the resultant vector. It relates to the improvement of the device.
[0002]
[Prior art]
Conventionally, a vibration compacting machine of this type that changes the rotation phase of one eccentric pendulum with respect to the other eccentric pendulum of a pair of eccentric pendulums in a vibration generator and gives the aircraft forward and backward movement by the resultant vector. As the forward / reverse switching mechanism, the rotation of the forward / reverse lever is transmitted to the rotation switching mechanism of the eccentric pendulum by mechanical means via a link or cable, and the hydraulic power is generated by the rotation of the forward / backward lever. It is known to transmit to the rotation switching mechanism of the eccentric pendulum by the hydraulic power means. Examples of using the hydraulic power means include, for example, Japanese Patent Publication No. 61-48997, Japanese Patent Laid-Open No. 63-60306, Japanese Patent Publication No. 5-17323. No. 6, JP-A-6-33413, and JP-A-7-286306.
[0003]
Those using hydraulic power for the forward / reverse switching mechanism of the above-described vibration compactor include a hydraulic cylinder of a forward / reverse switching shaft that changes the phase of the eccentric pendulum in the vibration generator, and a forward / reverse lever provided on the handle of the fuselage. A hydraulic hose is connected to the forward / reverse switching hand pump, and the piston in the forward / reverse switching hand pump is moved by operating the forward / reverse lever to move the hydraulic pressure to the hydraulic cylinder of the forward / reverse switching shaft in the vibration generator. Tell.
[0004]
In addition, among the devices using hydraulic power for the above-described forward / reverse switching mechanism, in a relatively large vibration compaction machine having a body weight of 300 kg or more, a machine generated on the forward / reverse switching shaft by the rotation of the eccentric pendulum of the vibration generator No. 61-48997, since the return force of the forward / reverse switching hand pump provided on the body handle or the like cannot be countered even if the lever is manually rotated. As disclosed in JP-A-63-60306 and JP-A-7-286306, a hydraulic pump is interposed between the hydraulic cylinder of the forward / reverse switching shaft in the vibration generator and the forward / reverse switching hand pump on the body handle. Thus, a servo mechanism that can supply auxiliary pressure from the hydraulic tank is provided.
[0005]
On the other hand, among those using hydraulic power for the forward / reverse switching mechanism, in a general-purpose vibration compactor having a body weight of 300 kg or less, a mechanical return force generated on the forward / reverse switching shaft by rotation of the eccentric pendulum of the vibration generator The forward / reverse lever of the forward / reverse switching hand pump provided on the body handle or the like can be manually rotated easily with respect to this mechanical return force. It is not necessary to provide a hydraulic auxiliary servo mechanism between the cylinder and the forward / reverse switching hand pump on the machine handle, but as a forward / reverse switching hand pump provided on the machine handle, the forward / reverse switching hand can be switched with a light operating force. A pump is known from JP 2000-17607.
[0006]
[Problems to be Solved by the Invention]
In a lightweight vibration compactor with a weight of 300 kg or less, the mechanical return force generated on the forward / reverse switching shaft due to the rotation of the eccentric pendulum of the vibration generator is not so large. Therefore, a switching hand as disclosed in Japanese Patent Laid-Open No. 2000-17607 The pump has the advantage that the forward / reverse lever of the forward / reverse switching hand pump can be easily turned manually by facing the mechanical return force. In this case, in the switching hand pump disclosed in Japanese Patent Laid-Open No. 2000-17607, when switching the machine body from reverse to forward, the cam of the lever rotating shaft is separated from the piston in the pump body, and this piston is used as the forward / reverse switching shaft. The mechanical return force will follow the direction of the cam already rotating forward, so the mechanical return force will gradually phase the eccentric pendulum in the forward direction without any trouble. Advance.
[0007]
On the other hand, in the above switching hand pump, when the machine body is switched from forward to reverse, the piston is pushed out in the direction opposite to the mechanical return force generated in the forward / reverse switching shaft by the rotational force of the cam of the lever rotation shaft. When a worker pushes the lever in the reverse direction at once, resisting the mechanical return force, the piston in the switching hand pump body is suddenly pushed out, and the phase in the reverse direction of the eccentric pendulum is rapidly performed. It will be. As a result, as shown in FIG. 6, the airframe tries to move backward rapidly from the forward movement, and moves backward with the rear end B of the compression plate A tilted with the rear end B of the compression plate A as a fulcrum so as to float. In other words, the road surface D that has been squeezed forward by turning forward is caused to move up and dig up by the rear end B of the squeezing plate A, thereby causing a problem of inhibiting an appropriate squeezing action. become.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems in the conventional light-weight type vibration compactor of the present invention, the present invention is an improvement of the forward / reverse switching shaft in the vibration generator, which allows the worker to move forward and backward. Even if the pressure oil in the switching hand pump body is suddenly pushed into the hydraulic cylinder in the direction resisting the mechanical return force by pushing the lever against the mechanical return force and pushing it into the reverse position at once. The spring in the forward / reverse switching shaft provided in the driven shaft of the vibration generator absorbs a part of the pushing force, so that the phase in the backward direction of the driven shaft eccentric pendulum is not rapidly performed, and the mechanical return It is an object of the present invention to provide a forward / reverse switching device capable of smoothly shifting the phase of the eccentric pendulum in the reverse direction while gradually resisting the force so that the airframe can smoothly shift to the reverse direction.
[0009]
The invention according to claim 1 is a forward / reverse switching device provided on a forward / reverse switching shaft of a vibration generator as a specific means for that purpose, and is provided with a cylindrical shape having an eccentric pendulum that changes the phase with respect to the drive shaft eccentric pendulum The driven shaft, a hydraulic cylinder projecting from one end of a vibration body case coaxial with the driven shaft, and a forward / reverse switching shaft inserted into the driven shaft and the hydraulic cylinder. The forward and backward switching shafts are connected to the outer periphery of the driven shaft through the piston inserted into the hydraulic cylinder and the long holes provided along the axial direction of the driven shaft, with both ends of the pins projecting in the direction perpendicular to the axial direction. It is composed of a base shaft portion in a driven shaft engaged with a spiral groove on the inner wall of the boss of the fitted driven gear, and a spring disposed in the driven shaft between the base shaft portion and the piston. And
[0010]
The forward / reverse switching shaft is configured such that the piston of the forward / reverse switching shaft is moved to the outermost position in the hydraulic cylinder by the mechanical return force generated in the forward / reverse switching shaft by the rotation of the spiral groove on the boss inner wall of the driven gear. Even when pushed out, the flange-shaped end of one end of the piston rod extending to the back surface of the piston is located inside one end of the cylindrical driven shaft, and the base end of the forward / reverse switching shaft and the flange-shaped end of the piston back surface It is preferable that the spring disposed between the two portions is always configured to be able to compress and expand within the driven shaft.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The configuration of the forward / reverse switching device according to the present invention will be described with reference to an embodiment shown in the drawings. This forward / backward switching device is provided on a compression plate 2 of a vibration compactor 1 as shown in FIGS. 1 is composed of a forward / reverse switching shaft 4 of the vibration generator 3 and a forward / reverse switching hand pump 6 provided above the operation handle 5 of the vibration compactor 1. As shown in FIG. A hydraulic cylinder 7 provided at one end coaxially with the forward / reverse switching shaft 4 in the vibrator case 3 a for housing the vibration device 3 is connected to the forward / reverse switching hand pump 6 via a hydraulic hose 8. Yes.
[0012]
The vibration generator 3 has a drive shaft 11 that can transmit rotation from the engine 9 of FIG. 2 via a pulley 10, and a driven shaft 12 that is arranged in parallel to the drive shaft 11. An eccentric pendulum 13 is fixed, and a similar eccentric pendulum 14 is mounted on the driven shaft 12 so that the phase can be changed with respect to the drive shaft eccentric pendulum 13.
[0013]
A central portion of the driven shaft 12 is provided with a driven gear 16 that is rotatable with respect to the shaft 12 and that is not movable in the axial direction. The driven gear 16 is a central portion of the drive shaft 8. Rotation is transmitted from the drive gear 15 fixed to the motor. The driven gear 16 is provided with a spiral groove 18 inclined on the inner wall of the boss 17 with respect to the axis of the boss 17.
[0014]
On the other hand, the driven shaft 12 has a cylindrical shape, and in the portion where the driven gear 16 is located, elongated holes 19 are formed in the axial walls of the opposing shaft walls along the axial direction, respectively. 12, the forward / reverse switching shaft 4 is inserted so as to be rotatable and movable in the axial direction.
[0015]
The forward / reverse switching shaft 4 is a piston that is slidably inserted into a base shaft portion 20 having a thickness that slides with the inner peripheral surface of the driven shaft 12 and a hydraulic cylinder 7 that projects from one end of the vibration body case 3a. 21, and a spring 22 disposed between the base shaft portion 20 and the piston 21.
[0016]
A piston rod 21a having a flange-shaped end portion 23 having the same diameter as the base shaft portion 20 at the rear end thereof is extended on the rear surface of the piston 21 via a bearing 21b so as to be rotatable. 1, even when the piston 21 is pushed out to the position in the outermost direction (right side) in the hydraulic cylinder 7 as shown in FIG. The spring 22 located inside one end of the shaft 12 and disposed between the base shaft portion 20 of the forward / reverse switching shaft 4 and the flange-shaped end portion 23 of the piston rod 21a is always compressed in the driven shaft 12. It is comprised so that expansion | extension can be repeated.
[0017]
Pins 24 are embedded in the base shaft portion 20 of the forward / reverse switching shaft 4 so as to be orthogonal to the axial direction of the switching shaft 4, and both ends of the pin 24 pass through the long holes 19 of the driven shaft 12. It is engaged in a spiral groove 18 in the inner wall of the driven shaft 12.
[0018]
In a state in which no external oil pressure acts in the hydraulic cylinder 7 in which the piston 21 at one end of the forward / reverse switching shaft 4 is inserted, if rotation from the drive gear 15 is transmitted to the driven gear 16, In the advance switching shaft 4, both ends of the pin 24 pass through the long hole 19 of the driven shaft 12 and engage with the spiral groove 18 in the inner wall of the driven gear 16. With the angular direction and the rotational direction of the driven gear 16, a mechanical return force that is pushed in the right direction in FIG. The state in which the forward / reverse switching shaft 4 is moved to the rightmost side in the drawing is a phase in which the eccentric pendulum 14 of the driven shaft 12 travels forward or backward, for example, at the fastest forward speed, with respect to the eccentric pendulum 13 of the drive shaft 11. It is rotated to the position.
[0019]
On the other hand, the hydraulic cylinder 7 into which the piston 21 at one end of the forward / reverse switching shaft 4 is inserted is connected to the front connection port 25 of the forward / reverse switching hand pump 6 provided outside via the hose 8. The forward / reverse switching hand pump 6 receives a mechanical return force in the rightward direction from the forward / backward switching shaft 4 in the driven shaft 12 by the spiral groove 18 of the driven gear 16. A mechanical return force is transmitted through the control unit, and the mechanical return force is overcome and the forward / reverse switching shaft 4 is pushed back in the opposite left (reverse) direction as shown in FIG. 5c.
[0020]
As the forward / reverse switching hand pump 6, as shown in FIG. 3, for example, one disclosed in Japanese Patent Laid-Open No. 2000-17607 can be used. The hand pump 6 is provided in a pump body 26 attached to the upper end of the operation handle 5 of the machine body. A cylinder 27 provided at a tip (left side in FIG. 3) of the body 26, A piston 28 inserted into the oil chamber 29, an oil chamber 29 provided at the other end of the pump body 26 (the right side in FIG. 3), a forward / reverse lever 30 pivotally mounted in the oil chamber 29, and the forward / backward lever 30 is provided with a cam 33 having a roller 34 in contact with a rod 32 protruding from the piston 28, and a connection port 25 provided at the tip of the piston 28 is connected to the hydraulic cylinder 7 of the vibration generator 3. And through the hose 8.
[0021]
The forward / reverse lever 30 is provided at both ends of a rotating shaft 31 that is mounted in an oil chamber 29 at the other end of the body 26 in a direction orthogonal to the axial direction of the cylinder 27, and is shown by a solid line in FIG. It rotates between the position and the reverse position indicated by the chain line. The relationship between the cam 33 and the piston 28 provided on the rotating shaft 31 is as shown by a solid line in FIG. 3, when the forward / reverse lever 30 is rotated in the forward direction, the cam 33 rotates to the right side, and the piston When the lever 30 is rotated in the backward direction as indicated by the chain line, the cam 33 rotates to the left side. Thus, the piston 28 is configured to be pushed to the left side against the mechanical return force from the direction of the forward / reverse switching shaft 4 of the vibration generating device 3.
[0022]
The piston 28 is provided so as to be pushed in the direction of an oil chamber 29 provided with a lever rotation shaft 31 by a spring 35 disposed on the connection port 25 side in the cylinder 27. The piston 28 is provided with a hollow portion 36 at an end portion (left side in FIG. 3) on the connection port 25 side, and has an inner diameter smaller than the hollow portion 36 on the lever rotating shaft 31 side of the hollow portion 36. A hole 37 is provided, and the rod 32 is inserted into the hole 37 so that the shaft end 32 a protrudes toward the lever rotating shaft 31. Further, as shown in FIG. 3, a pressure oil passage 38 communicating with the lever rotation shaft 31 side of the piston 28 and the inside of the hollow portion 36 is parallel to the hole 37 outside the hole 37 in the piston 28. Is provided.
[0023]
The rod 32 is provided with a ball 39 at the end on the connection port 25 side, and a flange 40 is provided on the outer peripheral surface closer to the lever rotation shaft 31 than the ball 39, and the flange 40 is hollow. By engaging with the step portion 41 at the boundary between the portion 36 and the hole 37, the rod 32 does not move in the direction of the lever rotation shaft 31.
[0024]
A valve seat 43 having a flow path 42 for closing the connection port 25 side end of the piston hollow portion 36 is provided at the end of the rod 32 provided with the ball 39 on the connection port 25 side. A spring 44 weaker than the spring 35 is interposed between the inner side and the flange 40 of the rod 32, and the rod 39 is pushed toward the lever rotating shaft 31 by the spring 44, whereby the ball 39 is moved to the valve seat. Apart from the flow path 42, a pressure oil flow path is formed between the left connection port 25 side and the right oil chamber 29 side in FIG.
[0025]
As described above, FIG. 3 shows a state in which the forward / reverse lever 30 is rotated to the forward movement position. In this state, the cam 33 is rotated to the right side of the drawing, so that the piston 28 is moved to the left spring. Under the pressure of 35 and the pressure oil generated by the mechanical return force from the direction of the forward / reverse switching shaft 4 of the vibration generator 3, it moves to the right in the cylinder 27, and the aircraft travels at the fastest forward speed. At the fastest forward position, the valve seat passage 42 opens when the rod 32 is pushed to the right side by the spring pressure of the spring 44, so that the pressurized oil in the cylinder 27 flows in the direction of the oil chamber 29 through the passage 38. In this state, the forward / reverse switching shaft 4 of the vibration generating device 3 is moved to the right side in the driven shaft 12 and the hydraulic cylinder 7 as shown in FIGS. 1 and 5a.
[0026]
On the other hand, when the forward / reverse lever 30 of the forward / reverse switching hand pump 6 is rotated in the direction of the reverse position as shown in FIG. 4, the pressure oil in the cylinder 27 of the hand pump 6 passes through the hose 8 and the hydraulic cylinder of the vibration generator 3. The piston 21 in the hydraulic cylinder 7 is pushed in the direction of the left driven shaft 12 as shown in FIG. 5b.
[0027]
As shown in FIG. 5 b, when the piston 21 in the hydraulic cylinder 7 is pushed in the left direction by the pressure oil from the direction of the forward / reverse switching hand pump 6, the forward / reverse switching shaft 4 moves between the piston 21 and the base shaft portion 20. Since the spring 22 is interposed therebetween, the pushing force of the piston 21 is not directly transmitted to the base shaft portion 20 as it is, but a part of the intermediate spring 22 absorbs the base shaft portion 20 from the movement amount of the piston 21. It is moved to a short distance, that is, to an intermediate portion of the spiral groove 18 in the driven gear boss 17.
[0028]
As shown in FIG. 5b, the fact that the base shaft portion 20 is located in the middle portion of the spiral groove 18 in the driven gear boss 17 means that the aircraft has not yet started to reverse, so to speak, it is in a neutral state during forward and backward movement. It has been moved to the position. On the other hand, in this state, since the pushing force of the pressure oil from the direction of the forward / reverse switching hand pump 6 is maintained in the hydraulic cylinder 7, this time, as shown in FIG. The spring force of the spring 22 thus pushed pushes the base shaft portion 20 toward the left side of the spiral groove 18, thereby moving the aircraft backward.
[0029]
【The invention's effect】
In the forward / reverse switching device of the present invention, the driven shaft 12 in the vibration generating device 3 and the forward / backward switching shaft 4 provided in the hydraulic cylinder 7 coaxial with the driven shaft 12 are interposed between the piston 21 and the base shaft portion 20. Since the spring 22 is mounted, the piston 21 directly pushes the base shaft portion 20 into the spiral gear 18 in the driven gear boss 17 even when the operator pushes the lever 30 against the mechanical return force and pushes it to the reverse position at once. The piston 21 compresses the spring 22 in the hydraulic cylinder 7 and absorbs the impact force from the piston 21, and then the repulsive force of the spring causes the basic shaft. The part 20 is moved to the left side position of the spiral groove 18 in the driven gear boss 17 and the reverse drive is started.
[0030]
Accordingly, since the mechanical return force in the vibration generator is small, such as a light weight type pressure machine with a body weight of 300 kg or less, the operator pushes the lever 30 against the mechanical return force and pushes it to the reverse position all at once. Even when such an operation is performed, according to the forward / reverse switching device of the present invention, the spring 22 of the forward / reverse switching shaft 4 first absorbs the impact force, and then the repulsive force of the spring 22 causes the base shaft portion 20. Thus, the eccentric pendulum is phased in the reverse direction while gradually resisting the mechanical return force, and the airframe can be smoothly shifted to the reverse direction. As a result, according to the device of the present invention, the eccentric pendulum rapidly moves from the forward to the reverse when the lever is pushed into the reverse position at a stroke as occurs in this type of conventional pressure machine. By changing, it is possible to surely solve the problem that the aircraft tilts backward and the compaction plate kicks up the roadbed.
[Brief description of the drawings]
FIG. 1 is a plan view showing an internal structure of a vibration generator provided with a forward / reverse switching shaft according to the present invention.
FIG. 2 is a side view of a vibration compactor equipped with the vibration generator of the present invention.
FIG. 3 is a side view of the forward / reverse switching hand pump during forward operation.
FIG. 4 is a side view of the forward / reverse switching hand pump during reverse operation.
FIGS. 5A and 5B are partial plan views showing a moving state of the forward / reverse switching shaft according to the present invention from forward to reverse, where a is the fastest forward speed, b is neutral, and c is the fastest reverse speed.
FIG. 6 is a side view showing a phenomenon that occurs at the time of reverse switching of a conventional vibration compaction machine.
[Explanation of symbols]
1: vibration compactor 2: compression plate 3: vibration generator 3a: vibration body case 4: forward / reverse switching shaft 5: operation handle 6: forward / backward switching hand pump 7: hydraulic cylinder 8: hydraulic hose 9: engine 10 : Pulley 11: drive shaft 12: driven shaft 13: drive shaft eccentric pendulum 14: driven shaft eccentric pendulum 15: drive gear 16: driven gear 17: boss 18: spiral groove 19: long hole 20: base shaft portion 21: piston 22: Spring 23: Flange-shaped end 24: Pin 25: Tip connection port 26: Pump body 27: Cylinder 28: Piston 29: Oil chamber 30: Forward / reverse lever 30: Rod 31: Lever rotating shaft 32: Rod 33: Cam 34 : Roller 35: Spring 36: Hollow part 37: Small hole 38: Pressure oil channel 39: Ball 40: Flange 41: Step part 42: Channel 43: Valve seat 44: Spring

Claims (2)

A forward / reverse switching device provided on a forward / reverse switching shaft of a vibration generating device, a cylindrical driven shaft having an eccentric pendulum that changes a phase with respect to a drive shaft eccentric pendulum, and a shaft on the same axis as the driven shaft. The hydraulic cylinder includes a hydraulic cylinder protruding from one end of the vibrating body case, and a forward / reverse switching shaft inserted into the driven shaft and the hydraulic cylinder, and the forward / backward switching shaft is inserted into the hydraulic cylinder. Through the long hole provided along the axial direction of the piston and driven shaft, both ends of the pin projecting in the direction orthogonal to the axial direction to the spiral groove on the boss inner wall of the driven gear fitted to the outer periphery of the driven shaft A forward / reverse switching device for a vibration compactor comprising a base shaft portion in an engaged driven shaft and a spring disposed in the driven shaft between the base shaft portion and the piston. When the piston of the forward / reverse switching shaft is pushed out to the outermost position in the hydraulic cylinder by the mechanical return force generated in the forward / reverse switching shaft due to the rotation of the spiral groove on the boss inner wall of the driven gear However, the flange-shaped end of one end of the piston rod extending to the back surface of the piston is positioned inside one end of the cylindrical driven shaft, and the base shaft portion of the forward / reverse switching shaft and the flange-shaped end portion of the piston back surface 2. A forward / reverse switching device for a vibration compaction machine according to claim 1, wherein the spring disposed between them is configured to always perform compression and expansion within the driven shaft.

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